Spoilerless flat wiper blade assembly and method of assembly

ABSTRACT

A wiper blade assembly has a resilient wiper element with a crown having lengthwise grooves and a tip for wiping a window. An arcuate metal flexor has inner edges disposed in the grooves of the crown and outer edges. An elongate cover has an upper wall and a pair of flanges curled inwardly in spaced relation from the upper wall to provide elongate channels. The outer edges of the flexor are disposed in the channels. The connector is configured for attachment to a wiper arm, and has a lower surface with a pair of flanges curled in spaced relation from the lower surface to provide opposite facing pockets that slidingly receive the cover flanges therein. A projection on one of the connector or the cover is received in an opening of the other of the connector or the cover to lock the connector to the cover.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application Ser.No. 60/939,510, filed May 22, 2007, and U.S. patent application Ser. No.12/124,623, filed May 21, 2008, which are incorporated herein byreference in their entirety.

BACKGROUND OF THE INVENTION

1. Technical Field

This invention relates generally to wiper blade assemblies for wipingwindows of a vehicle, and more particularly to spoilerless flat wiperblade assemblies.

2. Related Art

Wiper blade assemblies for vehicles are intended to maintain uniformcontact with a window across their length while oscillating to preventunwanted streaking from resulting on the window. Complicating matters isthe airflow generated over the wiper blade assembly while the vehicle ismoving, and while the wiper blade assembly changes its angle of attackrelative to the airflow while oscillating. Further complicating mattersis the non-uniform surface of the window, such that the wiper bladeneeds to be able to flex along it length to change its contour duringoscillation. As such, in an effort to best prevent unwanted streaks fromoccurring, numerous types of wiper assemblies have come about, many ofwhich are complicated to manufacture, and thus, tend to be costly.

One mechanism employed to maintain wiper blade assemblies in uniformcontact with the window is to incorporate spoilers on the assemblies.Spoilers are intended to create a desired aerodynamic attack of thewiper blade assembly relative to the airflow over the wiper bladeassembly, however, this approach is met with certain challenges. In somecases, the spoiler, rather than creating a uniform pressure distributionover the wiper blade assembly, can create unequal high and low relativepressures along an upper surface of the wiper blade assembly, and thus,portions of the assembly tend to lift from the window, thereby causingstreaking and/or noise. Further, the addition of spoilers to the wiperblade assemblies adds cost. As such, the challenges of forming a wiperblade assembly that is both aerodynamic throughout various conditions ofuse and yet low in cost, both in material and in manufacture, remains.

SUMMARY OF THE INVENTION

A wiper blade assembly constructed in accordance with one presentlypreferred embodiment of the invention has a resilient wiper element, anelongate flat metal flexor, an elongate polymeric cover, and a connectoradapted for attachment to a wiper arm. The wiper element has a crownwith longitudinally extending grooves therein and a neck extending fromthe crown to a body having a tip for engaging a window. The flexor has apredetermined curvature with inwardly facing edges and outwardly facingedges, wherein the inwardly facing edges are releasably disposed in eachof the grooves of the wiper element crown. The cover has a substantiallyflat elongate upper wall extending between opposite ends and a pair offlanges curled inwardly toward one another in spaced relation from theupper wall to provide elongate channels between the flanges and theupper wall, wherein the outwardly facing edges of the flexor arereleasably disposed in the channels. The upper wall of the cover has oneof an opening or a protrusion between the opposite ends. The connectoris adapted for attachment to a wiper arm, and has a lower surface forengagement with the upper wall of the cover. The cover also has a pairof flanges curled toward one another in spaced relation from the lowersurface to provide opposite facing pockets that slidingly receive atleast a portion of the flanges and the upper wall of the cover therein.The lower surface of the cover has the other of the opening orprotrusion, with the respective opening and protrusion being configuredto engage one another to lock the connector to the cover.

A wiper blade assembly constructed in accordance with another presentlypreferred embodiment of the invention has a resilient wiper element, anpair of elongate, arcuate metal flexors, an elongate polymeric cover,and a connector. The wiper element has a crown with longitudinallyextending grooves facing opposite one another and a tip for wipinglyengaging a window. The flexors have inwardly facing edges and outwardlyfacing edges extending along their length, wherein the inwardly facingedges are disposed in each of the grooves of the wiper element crown.The cover has a substantially flat elongate upper wall extending betweenopposite ends with an opening extending through the upper wall. Thecover also has a pair of flanges curled inwardly toward one another inspaced relation from the upper wall providing channels between theflanges and the upper wall, wherein the channels receive the inwardlyfacing edges of the flexors. The connector is adapted for attachment toa wiper arm and has a lower surface for engagement with the upper wallof the cover. The connector also has a pair of flanges curled inwardlytoward one another in spaced relation from the lower surface to provideopposite facing pockets slidingly receiving at least a portion of theflanges and the upper wall of the cover therein. The lower surface ofthe connector has a protrusion depending therefrom, with the protrusionbeing disposed through the opening in the cover to lock the connector tothe cover.

According to yet another aspect of the invention, a method of assemblinga wiper blade assembly is provided. The method includes providing aresilient wiper element having a crown with longitudinally extendinggrooves therein and a tip opposite said crown for engaging a window;providing an elongate, curved flexor have inwardly and outwardly facingedges; providing an elongate polymeric cover having an upper wall withone of an upwardly extending projection or an opening and a pair offlanges curled inwardly toward one another in spaced relation from theupper wall to provide elongate channels between the flanges and thewall, and providing a wiper arm connector having a lower surface withone of a downwardly extending projection or an opening and a pair offlanges curled toward one another in spaced relation from the lowersurface to provide a gap between the connector flanges and the lowersurface. The method further includes disposing the inwardly facing edgesof the flexor in the grooves of the resilient wiper element anddisposing the outer edges of the flexor in the channels of the cover.The method further includes sliding the wiper arm connector along thecover to an approximate midpoint thereof with the gaps of the connectorreceiving a portion of the upper wall and the flanges of the cover andbringing the projection into snapping, locked receipt within the openingto prevent relative movement of the wiper arm connector with the cover.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects, features and advantages of the presentinvention will become more readily appreciated when considered inconnection with the following detailed description of presentlypreferred embodiments and best mode, appended claims and accompanyingdrawings, wherein the same reference numbers are used to identifysimilar features, in which:

FIG. 1 is a side view of a wiper blade assembly constructed inaccordance with one presently preferred embodiment;

FIG. 2 is a cross-sectional view taken generally along line 2-2 of thewiper blade assembly;

FIG. 3A is a cross sectional view taken generally along line 3-3 of thewiper blade assembly;

FIG. 3B is a cross sectional view taken generally along line 3-3 of analternate construction of the wiper blade assembly;

FIG. 4A is a cross-sectional view taken generally along line 4-4 of thewiper blade assembly with a portion of a wiper arm connector constructedin accordance with one presently preferred embodiment;

FIG. 4B is a cross-sectional view taken generally along line 4-4 of thewiper blade assembly shown with a portion of a wiper arm connectorconstructed in accordance with another presently preferred embodiment;

FIG. 5 is a top plan view of a cover of the wiper blade assembly shownin a disassembled state;

FIG. 6 is a bottom plan view of the cover;

FIG. 7 is an end view of a wiper arm connector of the wiper bladeassembly;

FIG. 8 is a side view of a wiper blade assembly constructed according toanother presently preferred embodiment;

FIG. 9 is a partial plan view of the wiper blade assembly of FIG. 8 withan end cap removed therefrom;

FIG. 10 is a plan view of the underside of the end cap shown removedfrom the wiper blade assembly of FIG. 8;

FIG. 11 is a cross-sectional view taken generally along line 11-11 ofthe wiper blade assembly of FIG. 8; and

FIG. 12 is a cross-sectional view of the wiper blade assembly similar toFIGS. 4A-4B shown with a portion of a wiper arm connector constructed inaccordance with yet another presently preferred embodiment.

DETAILED DESCRIPTION OF PRESENTLY PREFERRED EMBODIMENTS

Referring in more detail to the drawings, FIG. 1 illustrates a wiperblade assembly 10 constructed according to one presently preferredembodiment of the invention. The wiper blade assembly 10 has a resilientwiper element 12 that is biased into a substantially uniform contactalong its length with a window to be wiped (not shown) by at least one,and shown here as a pair of separate, elongate, substantially flatflexor elements, referred to hereafter as flexors 14 (FIGS. 2-4). Thewiper element 12 and flexors 14 are carried by an elongate substantiallyflat cover 16, preferably constructed from a flexible polymeric materialof a suitable thickness, such that the cover 16 remains flexible in useso that it, along with the wiper elements 12, can be freely biased bythe flexors 14. The substantially flat contour of the cover 16 promotesthe ability of the wiper element 12 to maintain generally equalizedcontact pressure with the window during oscillation over a wide range ofvehicle velocity, and thus, over a wide range of air velocity. A wiperconnector 18 is adapted for attachment to the cover 16 without the useof separate fasteners. The connector 18 can be configured for attachmentto any wiper arm assembly (not shown), whether having a pin-typeconnection, hook-end type connection, flat-end type connection, orotherwise.

The polymeric wiper element 12 is fabricated from, for example, rubber,PTFE, or any other suitable wiper element material, as known in thewiper element art, and is shown here, by way of example and withoutlimitations, as being generally standard in form. The wiper element hasa crown 20 extending between opposite ends 21, 23 with longitudinallyextending grooves 22 opposite one another, extending laterally into thecrown 20. A neck 24 depends from the crown 20 to a body 26 thatterminates at a tip 28.

The flexors 14 are fabricated from a resilient metal, such as springsteel, for example. The flexors 14 are formed from separate strips ofmetal having an arcuate, bowed shape substantially along their length toform the finished bowed shape of the wiper blade assembly, as shown inFIG. 1. It should be recognized that the bowed shape of the flexors 14can be formed having any predetermined arcuate shape, depending on thecontour of the window to be wiped. Generally, the finished radius ofcurvature of the flexors 14 is smaller than the radius of curvature ofthe window, such that when the biased, pre-curved wiper blade assemblyis brought into contact with the window, the wiper blade assemblyapplies a uniform pressure to the window along its full length. Theflexors 14, as shown in cross-section in FIGS. 2-4, are generally flatand have opposite edges, with one edge being an inwardly facing edge 30and an opposite edge being an outwardly facing edge 32, extendingbetween opposite ends 33 (FIG. 3A, 3B).

The cover 16 has a substantially flat upper wall 34, shown here ashaving a slightly bulged or raised mid-portion 35 configured to receivethe crown 20 of the wiper element 12, and a pair of flanges 36 curledinwardly from the upper wall 34 toward one another. The flanges 36 arein spaced relation from the upper wall 34 to provide elongate channels38 between the upper wall 34 and the flanges 36, wherein the channels 38extend generally between opposite ends 40, 41 of the cover 16. The upperwall 34 has one of a downwardly extending projection or an opening,represented here, for example, as an opening 42 formed therethrough atan approximate midpoint between the opposite ends 40, 41. The opening 42facilitates assembly of the wiper connector 18 to the cover 16, asdiscussed hereafter. In manufacture, the cover 16 can be molded orextruded from the desired polymeric material.

The wiper connector 18 can be provided to enable attachment of one ormore types of wiper arms to the assembly 10. The connector 18 can befabricated from any suitable metal, such as stamped steel, or anysuitable polymeric material. As shown in FIGS. 4A-4B and 7, theconnector 18 has a lower wall 44 with a pair of laterally spacedsidewalls 46 extending upwardly therefrom to provide a generally openchannel 47 therebetween for receipt of an end of the wiper arm. Tofacilitate connection of the wiper arm to the connector 18, by way ofexample and without limitation, the sidewalls 46 can have oppositeopenings therein for receipt of a pin, or the sidewalls 46 can be moldedhaving inwardly extending projections 48 formed as one piece of materialwith the body of the connector 18. The lower wall 44 has a lower surface50 that abuts the upper wall 34 of the cover 16 upon assembly. Theconnector 18 has a pair of flanges 52 curled inwardly from the lowerwall 44 toward one another in spaced relation from the lower surface 50to provide opposite facing pockets 54 sized to receive at least aportion of the flanges 36 and upper wall 34 of the cover 16.

As shown in FIG. 4A, to facilitate assembly and retention of theconnector 18 to the cover 16, the connector 18 has one of an opening ora protrusion, and represented here, for example, as a protrusion 56depending from the lower surface 50 for receipt in the opening 42 of thecover 16. The protrusion 56 is preferably sized for a close snapping fitwithin the opening 42, such that upon being received therein, theconnector 18 is fixed against relative movement with the cover 16, suchthat separate fasteners are not needed. As shown in FIG. 4B, in additionto fixing the connector 18 to the cover 16, the protrusion 56 can beformed to extend through the opening 42 and beyond the upper wall 34into engagement with the crown 20 of the wiper element 12 sufficientlyto prevent relative sliding movement between the wiper element 12, thecover 16 and the connector 18. As such, upon assembling the connector18, the wiper element 12, cover 16 and connector 18 are fixed in theirrelative positions to one another without the need of additionalfasteners.

If the connector 18 of FIG. 4A is used, then it becomes necessary tofurther retain the wiper element 12 from moving relative to the flexors14 and cover 16. As such, as shown in FIG. 3A, the cover 16 is providedwith heat staked protrusions 58. The heat staked protrusions 58 areshown here, by way of example and without limitation, as being formedadjacent the ends 40, 41 in close proximity to the ends 23 of the wiperelement 12, thereby presenting an obstruction to the crown 20 of thewiper element 12 to prevent the wiper element 12 from moving along thelength of the channels 38. It should be recognized that the protrusions58 could be formed to extend into engagement with the crown 20 of thewiper element 12 at any position along the upper wall 34, if desired.

If the connector 18 of FIG. 4B is used, then it is unnecessary to useadditional, separate fasteners to further retain the wiper element 12from moving relative to the flexors 14 and cover 16. Rather, theprotrusion 56 of the connector 18, as explained above, engages andsufficiently retains the wiper element 12 against relative movement withthe flexor 14 and cover 16.

The flexors 14 can be fixed within the assembly by heat stakedprotrusions 60 in the cover 16. As shown in FIG. 3A, the heat stakedprotrusions 60 can be formed adjacent the ends 40, 41 in the upper wall34 of the cover 16. As such, the protrusions 60 extend downwardly intothe channels 38 to at least partially obstruct the channels 38 and thus,interfere with the ability of the flexors 14 to move relative to thewiper element 12 and cover 16. Rather than forming the protrusions 60 inthe upper wall 34, they can be formed in the flanges 36, such that theprotrusions extend upwardly into the channels 38 partially obstruct thechannels 38, as shown in FIG. 3B. As such, it becomes possible toconstruct the wiper blade assembly 10 so that the upper wall 34 of thecover 16 is completely free from indentations formed by heat staking, orotherwise.

As discussed above, if the connector 18 of FIG. 4A is used, then itbecomes necessary to further retain the wiper element 12 from movingrelative to the flexors 14 and cover 16. As such, in yet anotherpresently preferred embodiment, as shown in FIG. 8, end caps 62 areattached to opposite ends of the wiper blade assembly 10 to constrainthe wiper element 12, flexors 14 and cover 16 against relative movementwith one another.

As shown in FIG. 9, the flexors 14 have opposite ends 33 that extendbeyond the ends 40, 41 of the cover 16, with the wiper element 12extending to a predetermined location adjacent the ends 33. The flexors14 have notches or openings 65 adjacent their ends 33 for lockingengagement with the end caps 62. As shown in FIG. 10, to establish thelocking engagement of the end caps 62 with the flexors 14, the end caps62 have pockets for sliding receipt of the flexors ends 33 therein,wherein the pockets are represented here, by way of example, as beingprovided by flanges 66 curled toward one another in spaced relation fromupper walls 68 of the caps 62. In addition, the caps 62 have tabs 70extending downwardly from the upper walls 68, wherein the tabs 70 aresized for snapping, locking receipt in the openings 65 of the flexors14. Upon sliding the end caps 62 onto the flexors 14 and bringing thetabs 70 into snapping, locking receipt in the openings 65, the flanges66 of the end caps 62 preferably present themselves in close abutmentwith the ends 40, 41 of the cover 16, while an end wall 72 of the caps62 confronts the ends 21 of the wiper element 12, thereby preventingrelative movement between the wiper element 12, flexors 14 and cover 16.

In yet another presently preferred embodiment, as shown in FIG. 12, theprotrusion 56 of the connector 18 can extend not only into lockingengagement with the cover 16 and the crown 20 of the wiper element 12,but it can also extend into locking engagement with the flexors 14. Asshown here, by way of example and without limitation, the protrusion 56extends into an opening provided by recessed indentations or scallops 74in the flexors 14, thereby preventing the flexors 14 from movingrelative to the protrusion 56. As such, upon locking the connector 18into engagement with the cover 16, the wiper element 12, flexors 14,cover 16 and connector 18 are all locked against relative movement withone another, thereby completing the assembly of the wiper blade assembly10.

To assemble of the wiper blade assembly 10, the flexors 14 are disposedin the channels 38 of the cover 16, such as by sliding the outwardlyfacing edges 32 therein. Then, the crown 20 of the wiper element 12 isslid between the inwardly facing edges 30, wherein the inwardly facingedges 30 are received in the grooves 22 of the crown 20. Then theconnector 18 can be slid onto and along the cover 16 until theprotrusion 56 is received in snapping engagement in the opening 42 ofthe cover. As discussed above in the presently preferred embodiments,the protrusion 56 can be brought into engagement with the crown 20 ofthe wiper element 12, thereby locking the wiper element 12 againstrelative movement with the cover 16. In addition, the protrusion 56 canbe brought into locking engagement with the flexors 14, thereby lockingthe wiper element 12, the flexors 14, the cover 16 and the connector 18together. In the alternative, the cover 16 can be heat staked to bringthe protrusions 58 into obstruction with the wiper element 12 and/or theprotrusions 60 into obstruction with the flexors 14. Further yet, theend caps 62 can be snapped onto the ends 64 of the flexors 14, therebylocking the wiper element 12, flexors 14 and cover 16 together.

Many modifications and variations of the present invention are possiblein light of the above teachings. It is, therefore, to be understood thatwithin the scope of any allowed claims, the invention may be practicedotherwise than as specifically described.

1. A method of assembling a wiper blade assembly, comprising: providinga resilient wiper element having a crown with longitudinally extendinggrooves therein and a tip opposite said crown for engaging a window;providing an elongate, curved flexor have inwardly and outwardly facingedges; providing an elongate polymeric cover having an upper wall withone of an upwardly extending projection or an opening and a pair offlanges curled inwardly toward one another in spaced relation from theupper wall to provide elongate channels between the flanges and thewall; providing a wiper arm connector having a lower surface with one ofa downwardly extending projection or an opening and a pair of flangescurled toward one another in spaced relation from the lower surface toprovide a gap between the connector flanges and the lower surface;disposing the inwardly facing edges of the flexor in the grooves of theresilient wiper element; disposing the outwardly facing edges of theflexor in the channels of the cover; and sliding the wiper arm connectoralong the cover to an approximate midpoint thereof with the gaps of theconnector receiving a portion of the upper wall and the flanges of thecover and bringing the projection into snapping, locked receipt withinthe opening to prevent relative movement of the wiper arm connector withthe cover.
 2. The method of claim 1 further including providing thewiper arm connector with the downwardly extending projection and thecover with the opening.
 3. The method of claim 2 further includingpreventing relative movement between the wiper arm connector, the coverand the wiper element by engaging the crown with the projection uponbringing the projection into snapping, locked receipt within theopening.
 4. The method of claim 2 further including preventing relativemovement between the wiper arm connector, the cover, the wiper elementand the flexor by engaging the crown with the projection and bringing aportion of the crown and the projection into receipt within an openingin the flexor upon bringing the projection into snapping, locked receiptwithin the opening in the cover.
 5. The method of claim 2 furtherincluding providing an end cap and snappingly engaging the end cap withthe flexor to prevent relative movement between the flexor, the wiperelement and the cover.
 6. The method of claim 2 further includingproviding the flexor as a pair a separate arcuate, flat metal strips.